Ok, I just have a couple questions about the trans in my car (THM-440T4).

GM'* recommendation is to flush the fluid and replace the filter every 15,000 miles.

Now the problem is, is that I'm not sure where I truly am right now with it.

See at 126,500 miles, I just DRAINED the fluid and replaced the filter with a Fram trans filter kit.

Then at 137,300 I took the car to the Havoline Quik Lube thingymajig place and they FLUSHED it, but did NOT replace the filter saying that "it is not required" and I know damn well it is, otherwise GM would say that it is. Now. So since I have drained and replaced, and then flushed but not replaced, the next time I do it, I will be doing it correctly. I will have it FLUSHED and have the filter REPLACED. But all I want to know is, WHEN should I do it? I mean, that filter has been in there for 15,000 miles....but the fluid has been changed twice. So now that the filter has been in for 15k, doesn't that mean it should be replaced now?

Also, I know what the first question is gonna be. YES the fluid is BRIGHT RED and smells just like normal used transmission fluid should smell. It was a little low today because when I changed it (15k ago) I slightly OVER tightened the pan so it leaks a little in the back.
And I used the cork gasket...yeah, yeah, I KNOW, don't say it.

The next time i have it done, I want to have it done at the dealership so I know it is done CORRECTLY, but I really don't even know what they are gonna charge for it yet, but im guessing its not gonna be cheap. Thing is tho, is that I don't want to spend my money yet on it if I don't have to! You understand I'm sure.

Thanks for helpin out.

I'm going to go with 15k here... the majority of filters and cars say 30k, but our wonderfully crappy transmissions.. could use that extra cushion of savior against failure. IMO, I'd change the filter and add new fluid every 15k and every other filter get it flushed. And due to recent flushing info... I highly recommend [and also would not do it any other way], but by having the fluid flushed at a shop with a proper transmission flushing machine. I will never recommend nor will I ever flush my transmissions using the cooler lines and running it through the gears.

well...umm, i spent $110 at that Havoline quik lube place and they didn't even replace the filter, do you mean to tell me that the dealer would only charge $80

but actually this trans has never seen such nice treatment, because i talked to the people who used to own it. and they said they had NEVER flushed it. And that was at 117, 500 miles.

Yes, when i got the car. The trans fluid was like the color of old oil. Yes, it was bad. Very, very bad.

But it shifts perfectly still so, I dunno.

but umm OSG, you saying you DO recommend flushing, or you don't? I was slightly confused by your post.

I believe in flushing, only because GM says, FLUSH TRANSMISSION & CHANGE FILTER EVERY 15,000 miles. So yeah.

I don't really trust this transmission all that much only because it had the original factory fluid in it for 15 years.

Yes I know failure is imminent, but I want to delay it as long as possible. I actually wonder how long our transmissions would last if we did change the fluid every 15k. :?:

anyways, thanks for the responses, and i am gonna call the dealership tomorrow and see how much they charge for the flush and filter.

I recommend flushes over filter changes, but only by a trans flushing machine. And not some POS pulled from the back of a pickup in a field back in '52. I have access to a flushing machine in our shop, and you really can't screw it up, put new fluid in where it says new fluid and hook up the trans cooler lines to it... and you're done. Not saying that it'* easy to screw up the backyard method, it'* just bad in theory, bad in practice. I just remember hearing that some people thought those machines could backflush crap fluid in there, when they can't... as long as you have qualified people doing it [and any idiot can], then it'* the best [and only way] to go.

I can tell you from first hand experiences, that if trans fluid is flushed regularly it will last forever. I have a corsica with 200k that leaks about .5qts/wk of atf and i gotta say that car shifts smoother, and engages nicer than my very well taken care of b'ville did before i blew her up [and this car is a giant POS that was NEVER well taken care of.. the pan gasket looks to be about original or at the very least 10 yrs old [and there is no way the filter is any newer]. The fact that car leaks so damn bad is the only reason it runs so damn good.

What i'm saying here guys, is maybe we should engineer a drip system that control leaks 1qt/mo.... then we could have our transmissions last forever, without the cost of flushes... and filter changes less regularly. This is going to be a revolution, people across the nation are going to be engineering leaks in their cars to keep them running good forever. Don't give a hoot, pollute! --will be the slogan.

Haha, sounds like a good idea, but then you have all those old ladies and everything who are the stereotype owners of these cars, and who don't even know that their car HAS a transmission let alone that they have to change the fluid.

yeah i don't mean just for b'villes but for general car owners everywhere... but I do agree that the market for b'villes are for the seniors of the world.. yet the majority of members here are youngins... especially true for the 87-91 guys [the best gen anyways].

YOU GOT THAT RIGHT! :P

If you drive normally and don't lay rubber at startups your trans should last a long time. Increase the odds by adding a cooler. Heat is the enemy of all transmissions.
Filters clog and pumps loose pressure but they can be changed and returned to life.
If you want long life:
Add a cooler, drive normally, change the fluid and filter.